1. Technical Field
An embodiment of the invention relates generally to optics, and in particular relates to optical grating couplers.
2. Description of the Related Art
Optical gratings are frequently used to redirect light in a waveguide into an optical detector external to the waveguide. Light that has been traveling transversely through the waveguide by reflecting off the waveguide's inner surface at shallow angles may be redirected so that it strikes the inner surface of the waveguide at a sharper angle that is greater than the critical angle of incidence, thus allowing the light to escape through the surface. After escaping, the light may impinge upon a detector. The detected light may then be used for various purposes, such as to receive an encoded communications signal that was transmitted through the waveguide. Unfortunately, this process may exhibit poor efficiency, with a large part of the redirected light not reaching the detector. Further, the cost of manufacturing the detector/optical coupler may be excessive due to the need to manufacture several items separately and then assemble them into a completed assembly.